diff options
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/kern_loader.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/sys/kern/kern_loader.c b/sys/kern/kern_loader.c new file mode 100644 index 0000000..cf51c72 --- /dev/null +++ b/sys/kern/kern_loader.c @@ -0,0 +1,112 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <sys/loader.h> +#include <sys/cdefs.h> +#include <sys/elf.h> +#include <sys/types.h> +#include <sys/syslog.h> +#include <vm/vm.h> +#include <vm/map.h> +#include <vm/physseg.h> +#include <string.h> +#include <assert.h> + +__MODULE_NAME("kern_loader"); +__KERNEL_META("$Hyra$: kern_loader.c, Ian Marco Moffett, " + "Kernel ELF loader"); + +#if !defined(DEBUG) +#define DBG(...) __nothing +#else +#define DBG(...) KDEBUG(__VA_ARGS__) +#endif + +#define PHDR(hdrptr, IDX) \ + (void *)((uintptr_t)hdr + (hdrptr)->e_phoff + (hdrptr->e_phentsize*IDX)) + +int +loader_load(const void *dataptr, struct auxval *auxv) +{ + const Elf64_Ehdr *hdr = dataptr; + Elf64_Phdr *phdr; + vm_prot_t prot = 0; + + uintptr_t physmem; + size_t misalign, page_count; + + int status; + const size_t GRANULE = vm_get_page_size(); + + void *tmp_ptr; + + if (auxv == NULL) { + DBG("Auxval argument NULL\n"); + return -1; + } + + if (memcmp(hdr->e_ident, ELFMAG, 4) != 0) { + /* Bad ELF header */ + DBG("ELF header bad! (Magic incorrect)\n"); + return -1; + } + + /* Parse program headers */ + for (size_t i = 0; i < hdr->e_phnum; ++i) { + phdr = PHDR(hdr, i); + switch (phdr->p_type) { + case PT_LOAD: + if (__TEST(phdr->p_flags, PF_W)) + prot |= PROT_WRITE; + if (__TEST(phdr->p_flags, PF_X)) { + prot |= PROT_EXEC; + } + + misalign = phdr->p_vaddr & (GRANULE - 1); + page_count = __DIV_ROUNDUP(phdr->p_memsz + misalign, GRANULE); + + physmem = vm_alloc_pageframe(page_count); + __assert(physmem != 0); /* TODO: Handle better */ + + status = vm_map_create(phdr->p_vaddr, physmem, prot, + page_count * GRANULE); + + __assert(status == 0); /* TODO: Handle better */ + + /* Now we want to copy the data */ + tmp_ptr = (void *)((uintptr_t)hdr + phdr->p_offset); + memcpy((void *)phdr->p_vaddr, tmp_ptr, phdr->p_filesz); + } + } + + auxv->at_entry = hdr->e_entry; + auxv->at_phent = hdr->e_phentsize; + auxv->at_phnum = hdr->e_phnum; + return 0; +} |